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Your stock/original head studs should be fine with 3.8. If you wanted to to replace, the factory Turbo Dilivar head studs are what Rothsport used on my 4.0 engine.
As 95_993 stated using the pinned cam gear is a good upgrade. My Web cams came with the cam sprocket keyway machined, but without the factory cam alignment tool slots. This allows adjusting cam timing vs fixed when using the factory tool. It also provides a mechanical pin cam sprocket lock vs the factory friction lock.
The machined oil groove is too improve oil flow at that camshaft bearing location, so I was told by Web. Very knowledgeable people I spoke to at Web before and after I purchased.
Any pics that you or others may have would be great. Without taking it apart in front of me, trying to visualize exactly what's being described around the adjustment and the pin. (maybe I just need to read it a 5th time)
So do I need new sprockets?
EDIT: OK, after reading your reply a few times, along with @95_993 I think I understand what's going on. Please correct me if I'm wrong but it sounds like on 96+ the sprockets are not keyed (woodruff key). Instead they need to be held in a specific position using some sort of factory alignment tool and then they are torqued down. The keyed sprockets forgo this and the need for the tool. Is that the gist?
If so, yes, I need new cam sprockets.
Last edited by boomboomthump; 03-17-2024 at 02:44 PM.
Thanks bud. Yes, was just digging through a few "964 cam sprocket back-dating" threads and confirmed as well via pics of what's going on...
Woodruff key slot on the camshaft + that smaller looking "cogged" flange is keyed to the camshaft + sprocket is aligned and pinned through whichever hole best aligns with the cogged backing flange once timing is dialed in. Then it's torqued down without fear of timing position changing.
@boomboomthump yes, the 2 piece early sprockets are the way to go. Timing the cams is pretty straight forward.
here’s my set up when I was timing the cams. Trick is getting and right in sync as well as appropriate advance. Another rennlister had a really nice 3D printed adapter for the crank with a digital indicator that worked great. You’ll also need 1 earlier 930/964 non-hydraulic rocker arm to use temporarily for the timing process.
as for the head studs, mine are still stock as I did not end up pulling them since I didn’t split my case, but SW strongly recommended the turbo studs IF i did. For a top end only, didn’t want to risk breaking a stud just to replace them. Lots of heating involved , etc. I will dig up the part #. My motor is still a 3.6 by the way.
I also sent all my rocker arms tonSteve. Weiner at the time to regrind all the faces so they wear in appropriately to new cam. I am sure Patrick Motorsports or someone else is a good source since Steve's passing.
here’s my set up when I was timing the cams. Trick is getting and right in sync as well as appropriate advance. Another rennlister had a really nice 3D printed adapter for the crank with a digital indicator that worked great. You’ll also need 1 earlier 930/964 non-hydraulic rocker arm to use temporarily for the timing process.
BTW, who makes the chain tensioner tool and the other one which is holding the Fowler dial?
Thanks! And same here (more tech, less market values)
Just checked out the Stomski website. Nice stuff. Between those two and the digidix, looks like I'm going to have to make an investment in some tools.
When you get there I will loan you my engine rebuilding tools. Mostly Stromski and a few home made ones.
But I used a dial indicator and mechanical degree wheel. The very nice Stromski indicator mount and the digital degree wheel will make the cam timing setting much quicker and easier but not necessarily needed.
And for your visual needs:
To my knowledge the X51 option was only available on ROW 993 from the factory. Three years ago I had a mechanical restoration of my 97 Carrera S done by EPE of Natick MA among the many issues addressed it was decided to upgrade to the 3.8. Since my track days are in the rear view mirror the rebuild entailed the use of the slip in 3.8 Mahle P&Cs, regrind of cams to RS spec and a re flash by I think Electromotive....I don't have the three page invoice in front of me but that's what I recall....a Guard LSD was another notable addition...the bottom end of the engine was not changed as 3.6 to 3.8 does make all that much of a difference. Among the reason I went the 3.8 slip in route is that it's arguably period correct. My understanding is that going to the 4.0 and ITB etc is a whole different ball game with many more changes required as others have said.
Good luck...I am subscribed an look forward to see what youdo
Yes, it was a factory-installed option available in Europe, Gulf countries, Singapore and Hong Kong only. It was also offered as a retro-fit kit available globally.
When you get there I will loan you my engine rebuilding tools. Mostly Stromski and a few home made ones.
But I used a dial indicator and mechanical degree wheel. The very nice Stromski indicator mount and the digital degree wheel will make the cam timing setting much quicker and easier but not necessarily needed.
And for your visual needs:
Much appreciated Mike! Those are way fancier than the tools I loaned you.
03-17-2024, 02:15 PM
(maybe I just need to read it a 5th time) 
